Electronic components generate waste heat energy when in use. This heat energy should be removed to mitigate a potential for component overheating and subsequent malfunction. Computer systems typically include a number of such components, or waste heat sources, that include, but are not limited to, printed circuit boards, mass storage devices, power supplies, and processors. For example, one personal computer system may generate 100 watts to 150 watts of waste heat and some larger computers with multiple processors may generate 250 watts of waste heat. Some known computer systems include a plurality of such larger, multiple-processor computers that are configured into rack-mounted components, and then are subsequently positioned within a racking system. Some known racking systems include 40 such rack-mounted components and such racking systems will therefore generate as much as 10 kilowatts of waste heat. Moreover, some known data centers include a plurality of such racking systems.
Some known data centers include methods and apparatus configured to facilitate waste heat removal from a plurality of racking systems. Moreover, some known data centers include a plurality of racking systems that have a plurality of configurations that are non-uniform with respect to component density and usage such that each racking system generates waste heat at a non-uniform rate as compared to the remainder of the racking systems. In such data centers, application of uniform heat removal methods and apparatus to such non-uniform waste heat generation sources may not be fully efficient and effective in waste heat removal.
Some data centers use outside air as an important source of cooling air. The characteristics and quality of outside air may vary widely, however, even at a given location. Aside from the significant changes in temperature and humidity that can occur with the change of seasons, environmental quality of the outside air may vary due to a myriad of external factors. For example, smoke, smog, and airborne by-products of industrial and/or agricultural activities can all affect usability of outside air for cooling purposes. These variations over time in availability, cooling capacity, and quality of outside air create challenges in effectively sizing and operating cooling air systems for a data center. For example, a mechanical cooling system that is sized for cooler, drier times of year may fail to provide adequate cooling in hot, humid weather. Conversely, a mechanical cooling system that is sized to provide effective cooling during hot, humid summer months may result in a system that is significantly oversized for cooler, drier times of year.
The various embodiments described herein are susceptible to various modifications and alternative forms. Specific embodiments are shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that the drawings and detailed description thereto are not intended to limit the disclosure to the particular form disclosed, but on the contrary, the intention is to cover all modifications, equivalents and alternatives falling within the spirit and scope of the appended claims. The headings used herein are for organizational purposes only and are not meant to be used to limit the scope of the description or the claims. As used throughout this application, the word “may” is used in a permissive sense (i.e., meaning having the potential to), rather than the mandatory sense (i.e., meaning must). Similarly, the words “include,” “including,” and “includes” mean including, but not limited to.